This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. This project will study 15 young adults (ages 18 to 25) who are currently in treatment for cocaine or stimulant dependence at Hazelden Fellowship Club (as well as 15 controls). We will study neurobiological abnormalities, neurocognition and impulsivity particularly as they are associated with the recovery process. Specifically, subjects will undergo neurocognitive testing and tasks measuring impulsivity at two time points: at the beginning of their stay and at approximately 60 days to assess brain recovery through the active process of treatment and abstinence. Both self-rating scales of impulsivity (Barratt Impulsivity Scale) and computer tasks measuring executive functioning will be done. Brain imaging scans would also be completed at these two time points for similar reasons. The brain imaging portion of the study will consist of MRI scans and GABA spectroscopy which will be conducted soon after admission to Fellowship club and at three months. Although the participants would essentially act as their own controls we also would recruit healthy controls matched on age, gender, socioeconomic status and thus would allow comparisons on these tests with normal controls. The same measures and scanning could be done with controls including a repeat scan at three months to measure normal variation in GABA. The goal of this project is to examine whether youth with cocaine or amphetamine dependence (who are in treatment) are more impulsive than controls, as well as to determine the underlying brain abnormalities that exist in people with cocaine or amphetamine abuse as measured by fMRI and GABA spectroscopy. Based on the results of the brain scans, we hope to determine whether brain recovery (e.g. amelioration of abnormalities) occurs in these subjects with addiction over a 2-month period of being in a recovery setting. Through the neurocognitive testing, we hope to determine whether these neurocognitive and behavioral measures of impulsivity are correlated with altered GABA levels. Finally, the researcher will examine if any of the changes observed on behavioral measures or the fMRI are associated with recovery outcomes.